Expendable submarine receiving antenna

ABSTRACT

An expendable radio communication antenna for use by a submarine submerged at a depth at which its permanent antenna installation is ineffective, comprising a buoyant capsule, having an opening extending between the interior and exterior of the capsule, for release from an ejection chamber of the submarine, a coil of lead-in wire confined within said capsule and having electrical insulation suitable for use in sea water, and being of sufficient length to extend between said submerged submarine and the surface, a free end of said wire extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for connection at the free end to radio communication equipment aboard said submarine, and secured at its other end to said capsule, said coil being of the type whereby the wire pays out freely from said capsule by spiraling off said coil when a tensile force equal to the buoyance of said capsule is applied between said coil and said free end of the wire, whereby said expendable antenna including a selected length of lead-in wire may be disposed in said ejection chamber of the submerged site with the free end of the lead-in wire electrically coupled to said radio communication equipment and released to buoyantly rise to the surface and whereby said antenna may be disposed of by severing the lead in wire at the submarine.

Waited States Patent 91 Tennyson EXPENDABLE SUBMARINE RECEIVING ANTENNA [75] Inventor: James J. Tennyson, Waterford,

Conn.

[73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington, DC.

[22] Filed: Apr. 26, 1960 [21] Appl. No.: 24,856

[52] US. Cl 114/20 R, 343/709, 343/719, 343/877, 340/4 [51] Int. Cl F42b 19/36, HOlg 1/34, H0lg 1/04 [58] Field of Search 340/1-6, 4; 343/709, 714, 719, 877, 881; 114/20 Primary Exarniner-Benjamin A. Borchelt Assistant Examiner-Thomas H. Webb Attorney, Agent, or F irm-Richard S. Sciascia; Arthur A. McGill V a! M9752 [5 7] ABSTRACT An expendable radio communication antenna for use by a submarine submerged at a depth at which its permanent antenna installation is ineffective, comprising a buoyant capsule, having an opening extending between the interior and exterior of the capsule, for release from an ejection chamber of the submarine, a coil of lead-in wire confined within said capsule and having electrical insulation suitable for use in sea water, and being of sufiicient length to extend between said submerged submarine and the surface, a free end of said wire extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for connection at the free end to radio communication equipment aboard said submarine, and secured at its other end to said capsule, said coil being of the type whereby the wire pays out freely from said capsule by spiraling off said coil when a tensile force equal to the buoyance of said capsule is applied between said coil and said free end of the wire, whereby said expendable antenna including a selected length of lead-in wire may be disposed in said ejection chamber of the submerged site with the free end of the lead-in wire electrically coupled to said radio communication equipment and released to buoyantly rise to the surface and whereby said antenna may be disposed of by severing the lead in wire at the submarine. a

6 Claims, 5 Drawing Figures be/rer/antty 9542,50 224M552 EXPENDABLE SUBMARINE RECEIVING ANTENNA This invention relates to transfer of radio signal energy between a radio communication equipment lo cated submerged under sea water and the atmosphere overlaying the sea water, and more particularly to an expendable compact antenna unit that may be rendered operable at a selected time for enabling transfer of radio signal energy between the underwater equipment and the atmosphere. Sea water does not propagate radio frequency energy; while a radio signal may penetrate a few feet through sea water under some conditions it will not penetrate sea water to any appreciable depth. Penetration distance is, in part, a function of signal strength and frequency and is greater for stronger signals and lower frequencies.

A submarine vessel generally is equipped with a permanent radio communication antenna installation for use when the submarine is surfaced, but when the submarine is submerged below the depth of sea water that the radio signals can traverse, the submarine cannot establish radio communication. Attempts have been made to provide an antenna for a deeply submerged submarine but results have left much to be desired.

An object of this invention is to provide a new and improved method .and apparatus for establishing a radio communication link between a submerged radio communication apparatus and the overlaying atmosphere.

A further object is to provide a compact, portable, expendable antenna for a submarine available in standby condition till used and when in use being readily severable from the submarine without interfering with submarine operation; a further object to provide the antenna in a form to enable a substantial number to be carried and stored by a submarine, to be readily manipulatable by personnel after minimum instruction for rendering the antenna operational through one of the ejection chambers of the submarine, such as the Hare tube ejection chamber, and also readily severable from the submarine so as not to impede rapid acceleration of the submarine if that becomes necessary.

A further object is to provide an expendable radio antenna for use by a submarine when deeply submerged and free of dmaage and maintenance problems due to ease of replacement by another like antenna.

A further object is to provide an antenna in accordance with the preceding objects for a stationary underwater installation.

This invention concerns signal transmission as well as signal reception. Signal transmission with this invention is low-power and short-range due to insulation limitations, being generally comparable to walkie-talkie power and range.

This invention also can be utilized by an underwater swimmer carrying self-contained underwater breathing apparatus (SCUBA) for establishing radio communication with a radio station that may be in a nearby airplane, ship or on a nearby shore. A swimmer working at considerable depth faced with danger or having an urgent message concerning an important discovery is severely handicapped by lack of communication eapability. If he wishes to relay news of his important discovery to the shore or ship or plane, he must come to the surface. Not only must he then terminate his reconnoitering activities to rise to the surface but in addition a considerable length of time perhaps as long as an hour must elapse before the swimmer can rise to the surface. because of the necessity for gradual decompression.

An object of this invention is to provide a compact, portable, expendable antenna for use by an underwater swimmer.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the follow ing detailed description when considered in connection with the accompanying drawing wherein:

FIG. 1 illustrates a simplified embodiment of the invention in operation,

FIG. 2 illustrates another embodiment provided with a buoyant length of wire,

FIG. 3 illustrates an alternate form of the structure in FIG. 1,

FIG. 4 illustrates an antenna portion usable with the embodiments of FIG. 1 or FIG. 3., and

FIG. 5 illustrates the portion of FIG. 4 attached to the embodiment in FIG. 1 or FIG. 3.

The embodiment in FIG. 1 illustrates broader aspects of the invention; it includes a compact package 11 of a continuous length of thin insulated conductor that pays out readily and a buoyant device 12 for towing or carrying the packaged insulated conductor from a radio communication apparatus 13 at an undersea submerged location toward the surface while paying out the conductor 14 to change it from compactly packaged condition 11 to lineal extended condition.

The conductor may be packaged like a ball of wrapping twine as commonly used in retail establishments where the ball is enclosed in a container with a small opening and that end of the twine at the inside of the ball is threaded through the small opening in the container and pulled through the opening as needed. In FIG. 1, the paying out end of the packaged conductor 11 is mechanically and electrically connected to the communication equipment 13 while the other end 15 is mechanically connected to the buoyant device 12. The insulated conductor 14 may be either solid or stranded. The advantage of a stranded conductor over a solid conductor in this invention is that it requires less tensile force for payout because of its greater flexibility; the advantage of a solid conductor over a stranded conductor is that for a given outside diameter of insulated conductor, greater strength and conductivity is obtained with a solid conductor. Choice is made on the basis of which consideration is more important under a known set of circumstances. For a given depth, a packaged stranded conductor will be larger than a packaged solid conductor. Insulating choice is wide including coatings of materials such as silicone, polyethylene and nylon. Conductor 14 may be commercial coaxial cable of the type that is less than 0.075 inch diameter. The buoyant means 12 is designed for sufficient buoyancy to lift or tow the entire conductor upwardly in the water when released and in addition for applying sufficient tensile force to the conductor 14 to cause .conductor ball 11 to pay out; the amount of positive buoyancy required for pay out is small compared to that required for lifting the packaged conductor. The size and strength of the container 12 is directly related to the depth at which it is intended to be used. The size increases with depth because of the increased length of conductor carried as a package therein and the increased displacement for buoyancy needed to lift the heavier container and heavier package of wire. The strength of the container must be sufficient to resist crushing collapse of the buoyant chamber due to increased pressure. Besides fabricating the container of 5 stronger materials and with greater wall thickness when intended for use at greater depth, sealed-in air spaces 5 which are suitable for buoyancy at lesser depths may need to be filled with liquid of low specific gravity to resist crushing when designed for release at great depths.

Whether released by a swimmer, submarine, or underwater installation, the container 12 reaches the surface after a period of time determined from experience. Water currents ensure complete payout of the conductor if any remains coiled therein after the container reaches the surface. To further ensure payout where the container is released by a swimmer, the swimmer may jerk the conductor downwardly. Where release is from a submarine, slight forward movement of the submarine will further ensure complete payout of the conductor. It is advantageous for the conductor to be substantially longer than the vertical distance to the surface from the selected depth for release because the conductor generally will not extend vertically due to water currents, minor obstacles, etc., and for the additional reason that the portion of the conductor just below the surface if at an angle to the vertical will detect signals that either are horizontally or vertically polarized. For at least several feet from the surface downward the extended conductor 14 intercepts radio signals and when transmitting that same conductor portion will radiate through the water into the overlaying atmosphere.

A swimmer can readily carry one of these packaged antennas attached to his belt. Because the positive buoyancy is slight, on the order of one pound, a small lead block can be removably fastened to the container if necessary, to neutralize the positive buoyancy until the antenna is used at which time the lead block is removed and the container 12 is freed for rising to the surface. As pointed out previously, the size of the container increases with the order of depth at which it is to be released for use. The size of the package may appear to be a limitation but within the range of depth in which swimmers generally work at the present time, the container size would not be too large. A submarine or underwater installation is free of this limitation. For depths on the order of 1,000 feet the container may be made about 3 feet long and about 6 inches diameter.

In FIG. 2 there is shown an embodiment including an additional feature for retaining l or more feet of the conductor 14 on or closer to the surface of the sea than is accomplished by the embodiment of FIG. 1. A short length, namely 1 or more feet 14 a of the conductor adjacent'the end 15a is provided with small distributed floats of cork, or other material of low specific gravity. The container 12 is provided with a chamber 16 to retain that end of the conductor to preclude entanglement with the ball 11a. When the ball is completely paid out the remainder of the conductor bearing the floats is paid out and tends to support that end of the conductor at or close to the surface. In use the upper end of the conductor may be readily oriented in a desired direction for maximum sensitivity by swimmer or submarine by slowmovement in the appropriate direction.

FIG. 3 illustrates an alternate structure for the embodiment in FIG. 1. The conductor is packaged in coil form 17 instead of in ball form and disposed in a container having an annular hermetically sealed chamber 18 for buoyancy. The coil may be wound on a mandrel, dabbed or painted with lightly adherent cement such as dilute rubber cement to hold the coil together during handling and during payout. After the coil is formed, it is removed from the mandrel and disposed in the container as shown. The inner end is threaded through a hole in a cap 19 which is then screwed into place in the container to confine the coil in the container. The coil pays out beginning with the innermost layer.

FIG. 4 illustrates another feature of this invention for use in combination with previously described devices. It includes a comparatively short insulated conductor 20 on the order of 1 foot to several feet in length and an hermetically sealed tube 21 of flexible accordion pleated material in compressed compact form. One end 22 of the wire 20 is secured to one end of the tubular member 21. The other end of the conductor 20 is connected to a pressure seal 23 connector sealed into an end of the tube 21. A small compressed gas container 24 having a valve 25 also is sealed into one end of the tube 21. The ends of the tube 21 are connected and/or otherwise sealed in place after the conductor 20, the

connector 23 and the bottle 24 are assembled therewith. A conventional mechanical switch 26 having a mainspring (not shown), an escapement (not shown), a manually releasable latch 27 for releasing the escapement to permit the mainspring to drive the switch mechanism at a rate controlled by the escapement, a shaft 28 coupled to the valve 25 for opening the valve, a latch restrained strong spring (not shown) for driving the shaft 28 for opening valve 25 when released by the switch mechanism after a predetermined period following actuation of the latch. The switch is adjusted to operate the valve between one to several minutes after the latch 27 is released, a period of time selected to permit the container to reach the surface before the valve is opened. A container 30 with a readily removable friction cap 31 supports and protects the compact tube 21. When the valve is opened the cap 31 is forced off and the tube 21 is expanded to a considerable multiple of its compact length and the conductor 20 is extended. The buoyant tube 21 lays on the surface retaining the conductor 20 in an advantageous position for transfer of radio signal energy. The conductor 20 is electrically connected to the conductor 14. The structure in FIG. 4 is joined to the structure of the other figures as shown in FIG. 5.

In general, the longer the portion of wire approximately at the surface, the stronger will be the signal. Preferably, the length of extended wire at or near the surface should be as long as possible.

For submarine use, the antenna is designed in the form of elongated cartridge for ejection from the submarines flare tube. The inner door of the submarines flare tube shall be provided with a special pressureproof end seal having a connector fitting for the wire 14 of the antenna for anchoring the wire and for electrically connecting the wire 14 to radio communication inside the submarine. A number of the antennas can be carried on a submarine. They may be designed either for predetermined depth ranges or all may include a length of wire 14 corresponding to the maximum submersion depth. In the latter instance, when an antenna is to be released from less than that depth, an appropriate portion of the wire 14 is withdrawn and severed from the selected antenna. Then the flare tube is readied and the inner door of the flare tube is opened. The antenna unit is disposed in the flare tube and the pay out end of the wire is connected to the fitting on the flare tube door. The mechanical timer switch, if there is one, on the antenna is activated. The flare tube inner door is closed, the outer door opened and the antenna is ejected. The container rises to the surface paying out wire 14 as it rises. The mechanical switch is designed or adjusted to cause the gas capsule to inflate the tube 21 a predetermined time after the switch is activated. The time interval is selected to allow adequate time for the antenna container to reach the surface.

The described antenna is expendable and inexpensive. it may be used over a range of depth. On a submarine it is effective during hovering and at low speed. The submarine can sever the wire by accelerating rapidly. To ensure severance at the flare tube, the wire may be formed with a reduced strength section where desired. The inflatable tube lends itself to various antenna configurations for omnidirectional very low frequency reception, high frequency reception using two coaxial lines and others. A small preamplifier or receiver may be provided in the container for increased sensitivity and to permit the use of a high tensile strength conductor 14 (i.e., steel). The conductor 14 may be a buoyant coaxial cable.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within 7 the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. An expendable radio communication antenna for use by a submarine submerged at a depth at which its permanent antenna installation is ineffective, comprising a buoyant capsule, having an opening extending between the interior and exterior of the capsule, for release from an ejection chamber of the submarine, a coil of lead-in wire confined within said capsule and having electrical insulation suitable for use in sea water, and being of sufficient length to extend between said submerged submarine and the surface, a free end of said wire extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for connection at the free end to radio communication equipment aboard said submarine, and secured at its other end to said capsule, said coil being of the type whereby the wire pays out freely from said capsule by spiraling off said coil when a tensile force equal to the buoyancy of said capsule is applied be tween said coil and said free end of the wire, whereby said expendable antenna including a selected length of lead-in wire may be disposed in said ejection chamber of the submerged site with the free end of the lead-in wire electrically coupled to said radio communication equipment and released to buoyantly rise to the surface and whereby said antenna may be disposed of by severing the lead in wire at the submarine.

2. An expendable receiving antenna for use by a submarine vessel or submarine installation having an ejection means and located submerged at a depth where an antenna installation that may be carried thereby is not effective comprising a buoyant capsule having a chamber and an opening extending between the chamber and the exterior of the capsule, for release through said ejection means, a compact package of thin conductor wire coated by electrical insulation impervious to sea water and of sufficient length to extend between the submerged submarine and approximately the water surface, confined within said chamber and secured at one end of said capsule and having a free end extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire prior to use, and for connection to a radio communica tion equipment aboard said submarine, said compact package of wire being of the type that pays out the wire from said capsule while substantially stationary relative to said capsule when said capsule rises buoyantly to es tablish a radio communication link between the submarine and the overlaying atmosphere.

3. An expendable antenna for use by a submarine when submerged under conditions wherein its permanent antenna installation is ineffective, comprising a buoyant capsule having a chamber and an opening extending between the chamber and the exterior of the capsule for release from an ejection means of the submarine, a compact package of thin antenna lead-in wire of sufficient length to extend between said submarine when submerged at a selected depth and the sea surface approximately, said lead-in wire being coated by electrical insulation impervious to sea water and confined within the chamber and secured at one end to said capsule and having a free end extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for electrical connection to a radio communication apparatus aboard said submarine, said compactpackage of wire being of the type that pays out the wire readily from said capsule without movement ofsaid package of wire relative to said capsule when a tensile force equal to the buoyancy of said capsule in sea water is applied be tween the wire package and the free end, a length of insulated antenna wire carried in compact form by said capsule, means carried by said capsule operable for extending said antenna wire from said capsule approximately at the sea surface after the capsule is released from the submerged submarine and is buoyed to the surface,. whereby said capsule may be disposed in an ejection chamber of said submarine and the lead-in wire connected through a pressure proof seal on a wall portion of the ejection chamber to said communication apparatus and the capsule ejected from said ejection chamber to buoyantly rise to the surface while continuously paying out said lead-in wire and upon reaching the surface region said antenna wire is extended from said capsule.

4. An expendable radio antenna for use with a radio communication apparatus while the latter is deeply submerged in water at a depth which makes impractical direct signal transfer between said apparatus and the overlaying atmosphere which comprises a compact package of insulated wire conductor for electrical coupling at one end to said apparatus and of a length approximately to extend from said submerged apparatus to the surface of the water said package of wire beingof the type that pays out upon application of tensile force between its ends, and means physically connected to the other end of said conductor and carrying the compact wire packaged in substantially stationary relationship relative thereto and selectively operable to rise in the water and tow said other end of said conduc- 5. An expendable antenna as defined in claim 4 further including an adhesive on said wire to normally retain said wire in said compact condition and operable to permit the wire to pay out progressively upon application of tensile force between its ends.

6. An expendable antenna for use with radio communication apparatus located beneath the surface of the sea which comprises a compactly arranged flexible elongate gas-tight bag, a first insulated wire conductor arranged compactly within said bag to extend when said bag is extended, a gas supply for filling and extending said bag, time delay means for activating said gas supply a predetermined time after actuation of said time delay means, a second insulated wire conductor arranged compactly whereby one end may be progressively payed out and extended upon application of tensile force between said one end and the compactly arranged conductor, the other end of said second conductor electrically connected to said first conductor, buoyant means carrying said'conductors, bag, gas supply and time delay means and operable to rise in the sea water therewith when the one end of said second conductor is retained and the buoyant means is released and operable to release said gas bag when charged with gas by said gas supply means, whereby if said second conductor is of sufficient length to extend from said radio communication apparatus to the surface, and said delay means is operable to actuate said gas supply in a time interval in excess of the time for the buoyant means to reach the surface, said bag and said first conductor is extended at the surface after actuation of said time delay means and release of said buoyant means. 

1. An expendable radio communication antenna for use by a submarine submerged at a depth at which its permanent antenna installation is ineffective, comprising a buoyant capsule, having an opening extending between the interior and exterior of the capsule, for release from an ejection chamber of the submarine, a coil of lead-in wire confined within said capsule and having electrical insulation suitable for use in sea water, and being of sufficient length to extend between said submerged submarine and the surface, a free end of said wire extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for connection at the free end to radio communication equipment aboard said submarine, and secured at its other end to said capsule, said coil being of the type whereby the wire pays out freely from said capsule by spiraling off said coil when a tensile force equal to the buoyancy of said capsule is applied between said coil and said free end of the wire, whereby said expendable antenna including a selected length of lead-in wire may be disposed in said ejection chamber of the submerged site with the free end of the lead-in wire electrically coupled to said radio communication equipment and released to buoyantly rise to the surface and whereby said antenna may be disposed of by severing the lead in wire at the submarine.
 2. An expendable receiving antenna for use by a submarine vessel or submarine installation having an ejection means and located submerged at a depth where an antenna installation that may be carried thereby is not effective comprising a buoyant capsule having a chamber and an opening extending between the chamber and the exterior of the capsule, for release through said ejection means, a compact package of thin conductor wire coated by electrical insulation impervious to sea water and of sufficient length to extend between the submerged submarine and approximately the water surface, confined within said chamber and secured at one end of said capsule and having a free end extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire prior to use, and for connection to a radio communication equipment aboard sAid submarine, said compact package of wire being of the type that pays out the wire from said capsule while substantially stationary relative to said capsule when said capsule rises buoyantly to establish a radio communication link between the submarine and the overlaying atmosphere.
 3. An expendable antenna for use by a submarine when submerged under conditions wherein its permanent antenna installation is ineffective, comprising a buoyant capsule having a chamber and an opening extending between the chamber and the exterior of the capsule for release from an ejection means of the submarine, a compact package of thin antenna lead-in wire of sufficient length to extend between said submarine when submerged at a selected depth and the sea surface approximately, said lead-in wire being coated by electrical insulation impervious to sea water and confined within the chamber and secured at one end to said capsule and having a free end extending freely through said opening in said capsule for withdrawal and severance of a selected length of said wire and for electrical connection to a radio communication apparatus aboard said submarine, said compact package of wire being of the type that pays out the wire readily from said capsule without movement of said package of wire relative to said capsule when a tensile force equal to the buoyancy of said capsule in sea water is applied between the wire package and the free end, a length of insulated antenna wire carried in compact form by said capsule, means carried by said capsule operable for extending said antenna wire from said capsule approximately at the sea surface after the capsule is released from the submerged submarine and is buoyed to the surface, whereby said capsule may be disposed in an ejection chamber of said submarine and the lead-in wire connected through a pressure proof seal on a wall portion of the ejection chamber to said communication apparatus and the capsule ejected from said ejection chamber to buoyantly rise to the surface while continuously paying out said lead-in wire and upon reaching the surface region said antenna wire is extended from said capsule.
 4. An expendable radio antenna for use with a radio communication apparatus while the latter is deeply submerged in water at a depth which makes impractical direct signal transfer between said apparatus and the overlaying atmosphere which comprises a compact package of insulated wire conductor for electrical coupling at one end to said apparatus and of a length approximately to extend from said submerged apparatus to the surface of the water said package of wire being of the type that pays out upon application of tensile force between its ends, and means physically connected to the other end of said conductor and carrying the compact wire packaged in substantially stationary relationship relative thereto and selectively operable to rise in the water and tow said other end of said conductor upwardly with sufficient force to progressively pay out the conductor and change it from its compact condition to extended condition and to support said other end approximately at the surface at least temporarily.
 5. An expendable antenna as defined in claim 4 further including an adhesive on said wire to normally retain said wire in said compact condition and operable to permit the wire to pay out progressively upon application of tensile force between its ends.
 6. An expendable antenna for use with radio communication apparatus located beneath the surface of the sea which comprises a compactly arranged flexible elongate gas-tight bag, a first insulated wire conductor arranged compactly within said bag to extend when said bag is extended, a gas supply for filling and extending said bag, time delay means for activating said gas supply a predetermined time after actuation of said time delay means, a second insulated wire conductor arranged compactly whereby one end may be progressively payed out and extended upon application of tensile force between said one end and the compactly arranged conductor, the other end of said second conductor electrically connected to said first conductor, buoyant means carrying said conductors, bag, gas supply and time delay means and operable to rise in the sea water therewith when the one end of said second conductor is retained and the buoyant means is released and operable to release said gas bag when charged with gas by said gas supply means, whereby if said second conductor is of sufficient length to extend from said radio communication apparatus to the surface, and said delay means is operable to actuate said gas supply in a time interval in excess of the time for the buoyant means to reach the surface, said bag and said first conductor is extended at the surface after actuation of said time delay means and release of said buoyant means. 